High-compression engine for lowtest fuel



B. c. FISHER 2,392,371 HIGH CO-MPRESSION ENGINE FOR LOW TEST FUEL Filed June 6, 1942 Jan. 48; 1946.l

2 sheets-sheet 1 `Il k lllllll ai! lllllllllli ATTNEY Jan- 8, 1946. B. c. FISHER 2,392,371 I lHIGH COMPRESSION ENGINE FOR LOW TEST FUEL.

Fiied June 6, 1942 2 sheetssheet 2 88 f4. 90 86 az 5 4, 83

' 79 57 v59 307/ I v 72 73 `|NVENTOR ATTORN Patented Jan. 8, 1946 mGrr-coMPnEssIoN ENGINE Foa Low.

'rEs'r FUEL Bernardi). Fisher, J'ersey City, N. J., assigner to Charles H. Warlleld, Westfield, Nr.1., Frederic l P. Wareld. Goldens Bridge, N. Y., and Bernard C. Fisher, Jersey City, N. J., as trustees Application June 6, 1,942, Serial No. 443,014

8 Claims. (Cl. 123-7182) This invention relates to internal combustion engines and particularly to such engines which are designed to have high compression. I

One of the' objects of the invention is to provide a high compression internal combustion engine which can utilize low test fuels without detonation.

Another object of the invention is to provide a high compression internal combustion engine with means to'relieve the high pressures developed by full load conditions so that detonation is prevented.

Still another object oi the invention is to provide a high compression internal combustion en.. gine with means ,to utilize yfor a useful purpose in connection with the operation of the engine that part oi the explosive pressures which are produced in the cylinders under full load conditions and would normally cause detonation.

The invention accordingly comprises the features of construction, combinations of elements, and arrangement of parts, which will be exemplied in the constructions hereinafter set forth, and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:

Fig. 1 is a side sectional elevational. View of a cylinder block and crank Shaft showing my improved invention with additiona1 parts of the engine shown in dot-and-dash lines;

Fig. 2 is an enlarged sectional front view imillgh one of the cylinders of the engine of Fig. 31s an enlarged sectional planvlew through glie ezngine head and taken on the line 3-3 of Fig. 4 is a sectional side elevational view of an engine block and crank shaft assembly showing ya modified form of the invention; and

Fig. 5 is an enlarged sectional front view taken on the line 5-4 of Fig. 4.

Referring now to Fig. 1 of the drawings, a four cylinder engine is shown having an engine block I3 provided with the cylinders I2, I3, and I4 in which operate the working pistons I5, I6, I1, and I8. 'I'he pistons are connected respectively by connecting rods I3, 20, 2| and 22 to the usual crank shaft 23.

A head 24 is provided for the eng'ine block I0 and carries the sparkvplugs 25 in the usual manner. This head, unlike the usual head is pro- 31, 33, and 33 of reduced diameter, so that a space vided with openings 2621, 28, and 33 which are` located directly above the working pistons and are alittle over nali' as large in diameter. These openings are provided with closing plugs 33, 3|, 32, and 33 which may be integrally connected with a cover plate 34 held in place by suitable stud bolts 35. The plugs 30, 3|', 32, and 33 are made to conform to the openings 26, 21, 28, and 23,

which are preferably circular, and the plugs are spaced from the plate 34 by integral portions 36,

' is provided between each plug and the plate 34.

The plugs 33, 3|, 32, and 33 are provided with piston rings 40,\4|, 42, and 43 which make a close fit with the interior of the openings, these being bored out similarly to a cylinder for the purpose.

The plugs 30, 3|, 32, and 33 do not move in the openings in the cylinder head, but the close fit of the piston rings which are provided on them permit leakage from the combustion spaceof the main cylinder into the spaces above the plugs 30,

3|, 32. and 33. The head 34 is provided with longitudinal grooves M, 45, and 4B which connect 26 the openings 26 and 21, 21 and 28, and 28 and 29,

so that all of these openings are connected together above the plugs 30, 3|, 32, and 33. At the center of the engine I provide a relief valve 41 which may be of any desired type and is shown in the drawing as a spring pressed ball seated upon an aperture leading from the groove 45 to the atmosphere.

In the operation of the engine, the piston rings 43, 3|, 42 and 3 are tight enough to prevent any leakage into the space above the plugs during the compression stroke. When the explosion takes places, there may be slight leakage past these rings into the spaces above theplugs, but A the pressure will soon build up in these spaces, since the relief valve 4l is held closed by the spring, until the pressure will be sufficient to prevent substantial leakage past the piston rings under ordinary reduced load operation of the engine.

However, as. soon as full load is applied to the engine and the throttle is wide open, the explosion pressures increase enormously in the com bustion chamber, caused by an increased amount of fuel in the combustion space and therefore in-v creased compression. As the explosion takes place some of the gases are forced upwardly past the piston rings 40, 3|, 32, and 43 into the spaces above the plugs 33, 3|, 32, and 33. Enough' of the gases leak up into these spaces at this time t0 Prevent detonation. If the full load and full throttle conditions are maintained, then the pres# lsures in these spaces begin to build up so much.

`preferably have overlapping joints, as indicated, -to cut down the leakage to a minimum. The

number required may be determined by a cutand-try method. By leaving the relief valve open,

rings may be added until the leakage is smallA enough so that it will not interfere with the nor- `mal operation of the engine .at reduced loads.

When this condition is obtained the number of rings will be suilicient. The relief valve 41 may then be adjusted by adjusting the pressure of the spring, so that it will open under full load conditions just sufliciently to prevent detonation.

This adjustment may be made by tighteningthe compression of the spring until detonation occurs and then releasing it slightly.

I have discovered that in order to eliminate detonation and stm maintain the efnciency of the engine by providing a leakage path for excess pressures developed at the time of the explosion, it is necessary to have a leakage path of extremely small cross-section and at the same time to have va leakage path which will open into the combustion space through a relatively long distance and adjacent that portion of the combustion space where the flame propagation, which causes-detonation, occurs. -'I'he arrangement illustrated complies with these requirements. The surfaces of the -plugs 39, 3|, 32, and 33 are flush with the underside of the head and the lowermost one ofthe rings 40, 4I, 42, and 43, in each case, is closely.

spaced from these lower surfaces. Thus, the opening of the leakage path is -a circle which is positioned slightly off center of the cylinder, as shown in Fig. 3, but which acts in effect like a relativelylong crack in the head and extends across a substantial distance of the upper end of the combustion space.

While I have found the arrangement disclosed in Figs. 1 to 3 to'beveffective in eliminating detonation vin high compression engines, I may also .-'utilize the pressures developed in the spaces above -the plugs for operating some device which cooperates in the running ofthe engine. Thus, in Figs. 4 and 5 I have disclosed a modified form of the invention in which the principle. of the leakage path is much the same. Here a four cylinder engine is shown with a cylinder block 55, having cylinders 56, 51, 58,' and 59 provided with working pistons 69. 6|, 62, and 63 connected by connecting rods 64,' 65, 66, and 61 to a crank shaft 68.

A head 19 is similar to the head 24 of Fig. 1 and is provided with openings 1|, 12, 13, and 14 into which are fitted the plugs 15, 16, 11, and 18. These plugs are held in position by a cover plate 19 which is secured upon the head 10 by bolts, not shown, similar to the bolts of Fig. 2. The plugs 15, 16, 11, and 18 are mounted upon thc plate 19 by means of posts 88, 8l, 82, and 83 which extend up from the plugs and are'secured against the upper and lower surfaces of the plate` 19 by suitable securing nuts which space the plugs from the plate, as indicated.

The plugs differ from those described in connection with Fig. 1 inthat each is Vprovided on the top surface with a exible gasket 84 which is secured against the upper surface of the plug by means of securing nuts. The 'gaskets may be made of leather, fiber, or other suitable material which will withstand the conditions of use. The gasket 84 is larger in diameter than4 the top of the plug and the outer edge thereof 'is turned up. as indicated at 85 in Fig. 5, to form a one-way seal for the leakage path, which acts similarly to the leather washer on a plunger pump. Gases can pass up past the piston rings into the space between the plug and the plate 19, but when they try to pass in the. other direction the edges of the gasket 84 are crowded into the space so as to prevent the return passage. This maintains a pressure in the space above the plug because any leakage past the rings caused by an explosion will tend to build up this pressure.

The openings 1|, 12, 13, and 14 are connected together by means of longitudinal grooves 86. 81, and 88 cut in the under surface of thefplate 19. as indicated, but. in-lthis case there is no relief valve. However, the duct 89 communicates with the space 1| at the forward end-of the engine and this duct leads to a flanged tting 99 to which the intake connection 9| of a-turbine 92 is connected. The turbine92-'is positioned-in front of the engine adjacent the fan and is provided with a shaft 93 upon which is mounted the blades 94 of an air supercharger 95 having an inlet manifold 96 which may open just behind the fan to receive air from it. vThe outlet 91 of the supercharger 95 may be connected to an air inlet manifold 98 leading Adirectly to the carburetor 99 which supplies the air and fuel mixture to 'the engine.

In the operation of this arrangement pressure is developed in the spaces between the plate 19 andthe plugs`15, 16, 11, and 18 as the. engine operates. These gases under pressure are forced out through the duct 89 into the turbine inletl 9| and drive the turbine 92, which in turn drives the super-charger 95 causing air to be drawn l through the intake 96 and forcing it under'pressure into the air intake of 'the carburetor.V

When the engine is' operating under idling or low-load conditions, the pressure may not be high -enough to operate the turbine, but'at these times additional air under pressure'is not necessary. However, at full load with wide vopen throttle the supercharger will operate. Thus, detonation is prevented and at the same time the extra pressures developed by ,the explosion, which would otherwise be wasted, are utilized to drive the supercharger.

It will thus be seen that I have provided a simple head for anl enginel which has no moving parts in it but which will eliminate detonation. By means of my invention, therefore, it is possible to operate a high compression engine on lowtestfuels which would ordinarily cause terrific detonation in such an engine with resultant loss vof power and deterioration of the various parts of the engine. I am able to eliminate this detonation by providing a very small leakage path for the excess pressures to escape and in the` modication of Figs. 4 and 5 I provide a means to utilize these excess pressures to aid in the operation of the engine.

While the-excess pressures have been shown in Figs. 4 and 5 as operating a supercharger, it will be evident that any small piece of engine equipment may be driven in this manner. Also. where such a piece of equipment is driven by these excess pressures, it is not as important to main tain the leakage at a minimum, because the loss ci efl'ciency in the explosion chambers is given back to the engineby the operation of the accessory.

Since certain changes may be made in the above article and diierent embodiments of the invention could be made without departing from the scope thereoi, it is intended that all matter contained in the above description cr shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intendedto cover all of the generic and specific features oi' the invention herein described, and all statements of the scope of the invention which as a matter of language might be said to fall therebetween.

Having described my -invention what I'claim as new and desire to secure by Letters Pate'nt is:

l. In a high compression internal combustion engine a cylinder, a working piston in said cylinder, a head for said cylinder, and means in said head to provide a leakage path of such small cross-section that explosive gases will leak into said path when pressures develop which would otherwise cause detonation, but said leakage path will not interfere with the normal operation of said engine. f

2. In a high compression internal combustion engine a cylinder, a working piston in said cylinder, a head for said cylinder, means in said head to provide a leakage path from said cylinder of such small cross-section that leakage along said path will occur when pressures develop which would otherwise cause detonation, but said leakage path will not-interfere with the normal peration of said engine, said path having an extended opening into said cylinder.

3. In a high pressure internal combustion engine a cylinder, a working piston in said cylinder',

` a head for said-cylinder, a separate chamber in said head, means to provide a leakage path from 'said cylinder into said chamber ofl such small cross-sectional area as substantially to prevent wise to cause detonation, the opening ci said leakage path into said .cylinder extending for a relatively long distance.

5. In a high pressure internal combustion engine, a cylinder, a working piston in said cylinder, a head on said cylinder, means providing a leakage path through said head, said means comprising a plug xed into an opening in said head and having a groove around the circumference thereof between said ring and the opening in said head being suiiicient to provide a very small leakage path through said head.

6. In a high pressure internal combustion engine, a cylinder, a working piston in said cylinder, a head on said cylinder, a chamber in said head.

. there being a circular opening between said chamthere being a. circular opening between said chainso that detonation would otherwise be caused.

I7. In a high pressure internal combustion engine, a cylinder, a working piston in said cylinder. a head for said cylinder, a separate chamber in said head, means to provide 'a leakage path from said cylinder into said chamber of such small cross-sectional area as substantially to prevent explosive gases from passing into said chamber 'except when said pressures are suiiicient other- Wise to cause detonation, and means to relieve the pressure in said chamber when it rises above a predetermined value.

8. In a high pressure internal combustion engine, a cylinder, a working piston in said cylinder. a head on said cylinder,fa chamber in said head,

ber and cylinder through said head, a plug xed in .said opening and conforming to the walls thereof, a groove around the circumference of said plug, anda piston ring in said groove, the clearance between said piston ring .and the walls of said opening being such that a leakage path is formed between said cylinder and said chamber such that explosive gases will pass into said chamber only when said pressures are s uiliciently high so that detonation would otherwise be caused, and means to relieve the pressure in said chamber when it rises above a predetermined value. f

- BERNARD C. FISHER.4 

